Gas-operated caulking gun



Jan. 7,, 1958 P. H. MILLER GAS-OPERATED CAULKING GUN Filed May 17, 1954 N ME I INVENTOR. /dz// )7, /%//r,

GAS-OPERATED CAULKING GUN Paul H. Miller, Berkley, Mich.

Application May 17, 1954, Serial No. 430,126 4 Claims. (Cl. 222-323) The present invention relates generally to caulking guns f h ortable type. More specifically, the invention re-' lates to a power-operated self-contained caulking gun suitable for home use and home maintenance.

Power-operated caulking equipment is presently used in theconstruction' of large buildings and in other commercial operations. Such equipment presently employed utilizes a remote source of caulking compound which is piped under high pressure to the point of application through rather lengthy hoses which are heavy and awkward to handle. The cost and weight of such equipment makes it uneconomical and inconvenient for mere occasional use such as in home construction and maintenance.

Portable hand-operated guns on the other hand have been utilized for practically all home construction and maintenance work. Such guns are relatively small, inexpensive and easily portable. They require, however, considerable eflort to operate, thus creating fatigue in the workman in a relatively short time. A most serious handicap of many hand-operated guns is the difficulty in maintaining uniform flow of caulking compound. The intermittent flow results in a non-uniform seam consisting of a series of humps and valleys.

The principal object, therefore, of this invention is to provide a hand-held caulking gun which is of light weight, easy to handle and possesses a self-contained power supply.

Another object of this invention is to provide a selfcontained power-operated caulking gun which will insure a smooth flow of caulking compound.

A further object of this invention is to provide a selfcontained power-operated caulking gun which is easily reloaded with either bulk compound or packaged tubes of compound and is easily disassembled for cleaning and refilling.

A still further object of this invention is to provide a self-contained power-operated caulking gun which is inexpensive to manufacture and operate.

A yet further object of this invention is to provide a power-operated caulking gun which utilizes inexpensive compressed gas cartridges as a source of power.

Other objects and advantages of the invention will become apparent in the description of the invention to follow, when taken in conjunction with the accompanying drawing in which the figure is a side elevation in section, showing the caulking gun of this invention.

As will be seen in the drawing, the caulking gun of this invention comprises an elongated cylindrical housing sealed on the one end by a removable cap 11 and on the other end by a removable cap and handle assembly 12. The cap 11 contains a central passageway 13 for discharge of fluid caulking compound. A discharge tip 14 screwed into the passageway 13 is provided to control the delivery of material discharging through the passageway 13. The discharge tip 14 may be of rigid metal or plastic, or of flexible plastic material such as polyethylene and the like. The cap 11 is screwed over the end of housing It an annular gasket or sealing member 15 being pro- 2,818,999 7 Patented Jan. 7, 1958 vided to insure a leak-proof seam. Similarly, the cap and handle assembly 12 is screwed over the other end of the housing 10, a similar annular gasket or sealing member 16 being provided to insure a leak-proof joint. The sealing members 15, 16 preferably are of the square cut type consisting of a ring of resilient rubber or synthetic' material. Other types of sealing members may be provided, if desired. The use of this type of construction reduces precision machining requirements.

The gun is provided with an elongated rod-like valveoperating member 20 extending for substantially the full length inside housing 10, the rod 20 being provided on the discharge end with a conically tapered valve member 21 adapted to seal discharge passageway 13. Valve member 21 is securely fastened to the rod 20, for example, by apin 22. The other end of rod 20 projects through the cap and handle assembly 12 and terminates in a Tsha'ped handle 23. A sealing member 24 is provided to prevent leakage of air or other gas out of the housing along the rod 20 in the region where it projects through the cap-12.

As illustrated in the drawing, the cap and handle assembly 12 comprise a circular cap portion 30 and an integral cylindrical pipe-like handle stub 31 projecting downwardly and at a comfortable angle with cap portion 30. A handle grip portion 32, in this instance shown as having a cylindrical shape, is screwed over the end of handle stub 31. The grip 32 is hollow and is: provided at the bottom of the chamber with a small vent hole 33. Seated inside near the end of the handle stub 31 is a resilient gasket or collar 34 adapted to receive and seal about the neck portion 35 of a compressed gas cartridge 36. Above the collar 34, there is provided an arrowshaped anvil or cartridge puncturing device 37. Just below the tip of the anvil 37, there is provided a small angular hole or passageway 38 which communicates with a passageway 39 in the handle stub 31 and cap 30, the latter extending from the anvil 37 upwardly to open into the interior of housing 10. When a gas cartridge is inserted in the handle grip 32 and the latter is then screwed down over the handle stub 31, the top surface of the cartridge neck 35 is forced against anvil 37 due to the advance effected by the screw fittings. The cartridge 36 is ruptured in this fashion, its gas content escaping through passageways 38 and 39 to reach the interior of housing 10.

The rod-like, valve-operating member 20 is provided with a free piston 40 which is adapted to move essentially the full interiorly-enclosed length of rod 20. The piston 49 is provided with a pair of outer sealing rings 41, 41 to prevent escape of gas along the outer edge of the piston and with an inner set of sealing rings 42, 42 to prevent leakage along rod 20. The .rings 41, 41 serve as piston rings. These sealing members, however, are preferably of resilient, compressible material rather than metal. O-rings may be utilized, if desired. A slight modification of piston design would permit the use of leather or rubber cups as seals, one on each side of the piston. Thus provided, the piston is free to move towards the right, as viewed in the drawing, under urging of gas pressure exerted behind it in space 43. Ahead of piston 40 is a space 44 adapted to be filled with a fluid or plastic-type caulking compound. When the piston 40 is urged to the right by gas pressure exerted in chamber 43, the caulking compound in chamber 44 will be pressurized. In the arrangement shown, the compound is constantly under pressure, since no means is provided to interrupt the flow of gas from cartridge 36. Under these conditions, therefore, when rod 20 is moved to the left, as viewed in the drawing, valve member 21 will be unseated and pressurized caulking compound will be discharged from chamber 44 out through passageway 13 and discharge tip 14. Reseating of valve 21 will interrupt and cut oil flow of caulking compound when desired by the operator.

Movement of rod 20 is achieved by means of an angularly-projectingtrigger 50 attached to cap 30 and handle stub 31, the trigger 50 being pivoted about pin 54 and having an upwardly-projecting portion 51 which engages a circular collar 52 which is locked in a desired position on rod 20 by means of a pin or set screw. A vspring clip 53, also attached to the cap 30, is curved outwardly and downwardly so as to fit over the outer edge of collar 52. Thus, when trigger 50 is squeezed against the handle -grip 32, the upper trigger projection 51 will urge the rod 20 in an outward direction against the force exerted by spring clip 53. This outward movement unseats valve member 21, as indicated above, and caulking compound is forced out through the tip 14. When,

however, the trigger 50 is released, spring clip 53 will close or reseat valve member 21 in the passageway 13. Springclip 53 will be assisted in closing passageway 13 by the static and kinetic forces exerted by the plastic, somewhat'viscous caulking compound on the rear portions of valve member 21. This insures a fast-closing characteristic which will prevent undue loss of caulking compound. I

The caulking gun of this invention is quickly and easily loaded with. caulking compound by the simple expedient of releasing the gas pressure contained in chamber 43. This is done by slight loosening of the thread connections between handle 32 and stub 31. This breaks the seal of collar 34 about the cartridge neck 35. The cartridge 36 then will discharge itself out through the opening 33 in the bottom of the handle grip 32. When the pressure is relieved, the cap 11 on the discharge end of the gun may be unscrewed from the housing 10. The spring clip 53 is then pulled upwardly to free it from contact with collar 52. When this is done, the

rod 20 may be withdrawn in a backward direction. This backward movement of rod 20 also will cause valve member 21 to contact the free piston 40 and pull it to the bottom or left-hand portion of the gun. The interior of the casing may then be fitted by hand with bulk caulking compound or by inserting one of the commercially-available plastic or metal foil or cellophane- Wrapped tubes of caulking compound. The cap 11 is then replaced and the rod 20 pushed forward as far as it will go and until valve member 21 is reseated in discharge passageway 13. The spring clip 53 is then hooked in position over collar 52. Finally, a new gas cartridge is placed in the grip 32 and the latter again screwed down on handle 31 to pressurize the piston 40. The gun then is ready for use.

If desired, the gun may be provided with a gas-controlling valve to permit opening the housing without discharging the gas cartridge. The latter may be located, for example, in passageway 39 and be connected to trigger 50. However, this arrangement is more costly, and moreover produces a lag in flow of caulking compound which is not desirable. The small gas cartridges are so inexpensive as to make the additional expense of a valve mechanism impractical for home use.

The caulking gun of this invention is adapted to use any of the small, commercially-available metal cartridges containing compressed gas. Especially adaptable to use in the gun of this invention are any of the small metal carbon dioxide cartridges made for use in seltzer bottles. Cartridges of this type are readily available and are quite inexpensive. When the gun is provided with adequate sealing members at all joints, even the smaller type of cartridge will supply enough gas at a pressure more than adequate to completely empty the gun. For example, the conventional carbon dioxide seltzer cartridge contains carbon dioxide under a pressure of about 835 pounds per square inch. The pressure and volume of gas available from such cartridges is more than adequate to force even the heaviest grades of gun type caulking compound out of the gun.

In operation, the caulking gun of this invention is simple to operate and provides a smooth, easily controlled flow of caulking compound. Once charged with caulking compound and a fresh gas cartridge, the gun is operated simply by pressing the trigger. When the trigger is released, the pressure in the gun and the spring clip insure a speedy and positive closing characteristic which will prevent continued delivery of caulking compound beyond that desired. The operation of the gun requires very little physical elfort on the part of the operator, making it possible for him more accurately to direct the discharge tip. The gun is light in weight and does not have awkward, heavy, pressure-type hoses attached. In addition, the gun is very easily made of inexpensive materials. Machining and finishing is kept to a minimum because of the use of the ring-like resilient sealing members. While the gun of this invention has been identified and described in connection with caulking and the use of somewhat viscous caulking compounds, it is readily apparent that it may be utilized to dispense other fluids such as sealer compounds, cements, adhesives, greases and other lubricants, and many other fluid-type materials.

While it will be apparent that the preferred embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A power-operated, fluid-dispensing gun comprising a cylindrical housing, a removable cap on one end of said housing containing a fluid discharge passageway, a hollow handle attached to the other end of said housing, a rod extending through said housing and carrying a valve member adapted to seat in said discharge passageway, a free piston carried onsaid r-od between said valve member and said handle, a compressed gas cartridge in said handle, means for conducting gas under pressure from said cartridge to a position in said housing behind said piston so as to urge the latter toward said discharge passageway, trigged means attached to said handle and operative to move said rod longitudinally so as to unseat said valve member, and means operative on said rod urging said valve member into normally seated position in said discharge passageway.

2. A gas-operated caulking gun comprising an elongated, cylindrical housing, a removable cap on each end of said housing, one of said caps containing a passage way for discharge of caulking compound, and the other of said caps containing a pressure seal fitted aperture, a hollow handle attached to the said last-named cap, a rod extending the length of said housing, said rod terminating at one end adjacent said discharge passageway inside said cap and projecting from said pressure seal fitted housing through the said aperture on the other of its ends, a valve member attached to the end of said rod in a position to close said discharge passage.- way, a free piston mounted on said rod in said housing between said valve member and said projecting rod end, means operative on said rod to maintain said valve member normally seated in said passageway, a compressed gas cartridge in said handle, means including a passageway for conducting gas under pressure from said cartridge to said housing to a position behind said piston so as to urge the latter toward said discharge passageway, and trigger means associated with said rod for moving said rod to unseat said valve member.

3. A gas-operated caulking gun comprising an elongated cylindrical housing, a removable cap on one end of said housing and containing a passageway for discharge of caulking compound under pressure, a removable closure means on. the other end of said housing,

said closure means having an aperture surrounded with a pressure-sealing means, a rod extending the length of said housing, projecting on the one end through said aperture in said closure means and on the other end terminating within said housing and adjacent to said discharge passageway, a valve member carried on the said last-named rod end in a position to close said discharge passageway, a free piston carried on said rod between said valve member and said closure means, means attached to said closure means forming a handle, said handle carrying means for supplying gas under pressure to a point behind said piston to urge the latter toward said discharge passageway, means attached to said closure means operative on said rod to unseat said valve, means attached to said closure means urging said valve into normally seated position, said valve being shaped to contact said piston as said rod is moved in the direction of said closure member whereby said piston is returned to a position adjacent to said closure member.

4. A dispensing gun having a hollow housing, removable discharge nozzle means attached to the forward end of said housing, said nozzle having a discharge passageway therein, handle means attached to the forward end of said housing, rod means extending longitudinally through said housing and terminating at its forward end in valve means adapted to seat against the interior surface of said nozzle and close said discharge passageway, the rearward end of said rod projecting through said handle means, free-floating piston means mounted on said rod in said housing in pressure-sealed relationship with said housing and said rod, means carried by said handle for supplying gas under pressure to the rearward end of said housing, triggering means associated with said rod operative to move said valve means and open said discharge passageway, and means associated with said rod urging said valve into normally closed position.

References Cited in the file of this patent UNITED STATES PATENTS 1,554,348 Hawkins Sept. 22, 1925 1,751,693 Gentle Mar. 25, 1930 2,363,023 Stewart Nov. 21, 1944 FOREIGN PATENTS 202,156 Great Britain Aug. 16, 1923 589,654 France June 3, 1925 653,042 France Mar. 15, 1929 U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent Not) 233%,???) Paul H, Miller January *3, 1958 It is hereby certified that error appears .in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

3011111111 5, line 23, for forw'ard" read. me rearward n sealed this 19th. of? June 1958,

KARL H, AXLINE ROBERT C. WATSON Attestlng Officer Conlnissioner of Patents 

